When Ronald Guzman and Nomar Mazara were 15, they were teammates in the Reviving Baseball in Inner Cities (RBI) program that won the Dominican Republic's first ever RBI championship.

Two years later, the two have reunited as teammates in the Rookie-level Arizona League after the Rangers awarded them the biggest bonuses on the international market in 2011, with $4.95 million going to Mazara and $3.45 million to Guzman.

A 17-year-old lefty first baseman, Guzman has hit .283/.336/.392 with nine walks and 29 strikeouts in 131 plate appearances. Toward the end of extended spring training, Guzman rolled an ankle, a minor injury that caused him to miss the first few games of the Arizona League season. When he got back on the field, like a lot of young hitters, Guzman seemed to be trying to show he could hit for power at the expense of what drew the Rangers to him in the first place—his hit tool.

"He was just a little pull happy," said Arizona League Rangers manager Corey Ragsdale. "There was a little too much body in his swing, so then he got back to trusting his hands, not necessarily trying to hit the ball 400 feet but using his hands, hitting the ball on the line, using the whole field. And he can. He uses the whole field, it's line drive after line drive. He's hit a lot of balls on the nose."

Several teams had Guzman ranked as the No. 1 player on the international market in 2011. Yet even scouts with some of those teams acknowledged that Guzman's bat speed was only fair and that his power didn't show up in games with much frequency, so the limited over-the-fence power—he hit his first professional home run yesterday—hasn't been a surprise.

It's also not unusual. David Ortiz hit two home runs in 53 games as an 18-year-old in the Arizona League. Miguel Cabrera hit two balls out of the park in 57 games in the Rookie-level Gulf Coast League when he was 17. While he's never been billed as a power bat, Guzman did flash his raw power in batting practice as an amateur and, at 6-foot-5, 205 pounds, he has the size that should lead to more juice eventually.

"He can sit up there in BP and yank balls, hit them out of the park, but he's a 17-year-old kid, a good kid, and I think he needs to learn how to hit, learn himself, do all that," Ragsdale said. "Then the power part, as he gets stronger, as he matures, that comes later down the road. He's going to hit for a high average, so I think that's the key now—learning how to hit, then let the power numbers come later on."

Guzman has also been dealing with a position change, moving to first base after trying out for teams in the outfield. Guzman was never blessed with great speed or arm strength, so scouts always viewed him as either a left fielder or a first baseman, the latter now being his full-time gig. He committed five errors in his first seven games, but he hasn't made one since.

"Where he's at now and last year in instructional league when I first saw him, it's a night and day difference," Ragsdale said. "That's a credit to him, the way he works. He gets out there every day, we take ground balls, work on footwork, do all that stuff. He has come a long, long way.

"The biggest thing was the footwork. For infielders, it's all about footwork, getting yourself into good position. Being 6-6, it's tough for him sometimes. He was still gangly and all that , but now that he's worked on it, he's done agility work and the footwork has gotten much better. I think that's the biggest thing that's helped him so far is learning how to use his feet to get in good position to field the baseball."

Mazara's bonus, a record for an international amateur player, was received with a heavy amount of skepticism in the international scouting community. Mazara has more raw power than Guzman, but getting to his pop has been problematic, to nobody's surprise. He's shown impressive raw power from the left side for his age, hitting .232/.367/.420 as a 17-year-old, but he's also leading the league with 42 strikeouts in 139 plate appearances.

"He's got easy pop," Ragsdale said. "He doesn't have to try to hit it hard or far; it jumps off the bat pretty well. We had a 30 mile an hour wind the other night blowing straight in after one of those dust storms and he hit one off the wall in right-center field, just a line drive where the ball jumped off the bat. When he gets it there, he doesn't have to try to hit it hard, the ball just jumps off the bat. We're just trying to get the barrel to the ball more consistently right now."

Therein lies the biggest challenge for Mazara and the main reason why so many scouts were skeptical about him being worth such a generous bonus. Mazara came into pro ball with an exaggerated leg kick which, combined with the length of his swing, led to timing issues and an alarming number of strikeouts. When Mazara was an amateur, one team saw him strike out in more than 10 straight at-bats. The concerns have held true so far, as Mazara has struck out in 30 percent of his trips to the plate.

The Rangers knew he would be a high-strikeout hitter, but they have at least tried to tone down Mazara's leg kick. As Ragsdale explained, he's quieter in batting practice, but when the game begins, he tends to revert to old habits, which disrupts his rhythm and causes a lot of his swings to come up empty.

"He's still working that timing out, but he's been swinging it better lately," Ragsdale said. "He's still been a little late on some pitches that normally he will hit, but he's had a pretty good zone discipline for the most part. He's handled the zone well and put some good swings on balls."

While Mazara must prove he can do more damage when the ball is in the zone, the 23 walks he's drawn have been a pleasant surprise. Like many young hitters, he'll still chase pitches with two strikes, but Ragsdale said he generally doesn't expand his zone much for his age. He's shown more patience than expected, something that's hard to judge at the Dominican amateur level, especially since some teams felt that Mazara's trainer didn't like to expose him in game situations.

In right field, Mazara has come a long way, according to Ragsdale.

"That's a credit to him," Ragsdale said. "We had a talk in the spring just about how he's going to get better during BP taking one hard round, which is 15 minutes of getting down there and chasing balls in the outfield. Some young kids have a tendency to be talking in groups, but I look up and he's getting his shagging in. From last instructs, he's so much more confident in what he's doing. Everything is much, much improved, and that's a compliment to him and how he's been working every day to get better in the outfield. His throwing is much improved. He has a very good arm in the outfield, very accurate from right field. He's done very well."